Overpopulation of wild animals, such as wild or feral hogs, can be problematic in a number of ways. Feral hogs may damage trees, vegetation, agricultural interests, and other property. The extent of property damage associated with feral hogs has been estimated to be as high as $800 million annually in the United States alone. In addition, feral hogs may prey on domestic animals such as pets and livestock, and may injure other animal populations by hunting them, destroying their habitat, and spreading disease.
The size and number of feral hogs in the United States contributes to their ability to cause damage to property and other animal populations. Mature feral hogs in the United States may be as tall as 36 inches and weigh from 100 to 400 lbs. Feral hog populations are also staggering. A publication by the Samuel Roberts Noble Foundation of Ardmore, Okla. estimated there were between 617,000 and 1.4 million feral hogs in Oklahoma in 2007, and the Texas Parks and Wildlife Department estimates that there are more than 1.5 million feral hogs in Texas, citing the animals' limited number of natural predators and high reproductive potential as underlying factors in the large population. Sows can produce up to ten piglets per litter and may produce two litters per year. Piglets reach sexual maturity at six months of age, allowing the hog population to quickly reach a state of overpopulation.
Because feral hogs are so numerous and have virtually no natural predators, in some areas it is desirable to artificially control their populations by trapping them. However, feral hogs are difficult to trap because they are relatively intelligent, have keen senses of hearing and smell, and quickly become suspicious of traps. In addition to being difficult to trap, the hogs' bulk and strength may render many traps unsuitable for capturing and holding multiple hogs.
A number of feral hog or animal traps and trapping systems exist today. Many trap designs are intended to trap one or only a small number of animals, commonly, animal-actuated traps. These traps are largely ineffective in controlling or impacting exploding feral animal populations. A smaller number of trap designs provide for a large corral-like structure to be constructed with the intention of capturing larger numbers of feral animals; however, these traps require considerable space, time and effort to construct and deconstruct. And, while such structures may be assembled on site, they are not readily portable. Given the fixed nature of these corral-systems (which include fixed panels that extend up from the ground), these systems typically require many days of visiting the site, baiting and training animals to overcome their suspicion. Lastly, there are a very small number of suspended trap systems that include animal-actuated systems (which have limited effectiveness) and/or require heavy-duty lift systems that require impractical or costly structures or complex cabling/pulleys as well as considerable applications of force to effect the raising and maintenance of a suspended trap above a trap site.
In addition to feral hogs, it may be desirable to trap a variety of other animals (e.g. burros, bears, and deer) and birds (e.g. geese) for purposes of urban encroachment, relocation, research or eradication.